4X4 Dis-engagement question

Hey whats up guys,
I was working on my 2006 FX4 the other day and had the front end jacked up. I spun the front wheel with my hand and noticed that the front axles, shafts, whatever you wanna call them, as well as the front driveshaft were spinning while i spun the wheel. the truck was in 2 wheel drive, and i saw a video on youtube showing how the F150 dis-engages the hubs at the outside of the half shafts, right at the wheel. Soo, since it wasn't in 4 wheel drive, why was all the front driveline rotating with the wheel. i thought none of that stuff was suppost to rotate while in 2 wheel to save wear and tear and vibration, etc? I thought maybe something was wrong the the dis-engaging mechanism so i went to the local dealer to ask if that was how it was suppost to be or not, and they gave me some half assed BS answer that made me feel no better about the situation. So i was just wondering if anyone could tell me for certain, is the front driveline suppost to rotate with the front wheels when it's in 2 wheel drive or is it suppost to dis-engage at the hub until 4 wheel drive is selected? thanks for the help guys. Oh, and Merry Christmas!

I noticed that there were no replies yet to this question. I cannot give you a definite answer but past experience revealed that grease in the diff would turn the forward drive shaft with the wheel turning, but if the drive shaft was held by hand, it would not turn with the wheel turning.

Might give that a try. I am sure googling the front hubs will give some additional information.

Was the truck idling? If the truck is not running there will not be any vacuum going to the hubs to disengage them. When you start the truck and its in 2-wheel drive the vacuum solenoid will send vacuum to the hubs to disengage them.